Researchers provide further evidence of how gene mutations in a certain brain region might fuel behaviors associated with obsessive-compulsive disorder. The findings could pave the way for new treatments for the condition.

Researchers reveal how certain gene mutations in the corticostriatal brain region might play a role in OCD-like behavior.

Obsessions include repetitive thoughts or mental images that trigger anxiety, while compulsions refer to the urge to repeat certain behaviors in response to obsessions. Common examples of compulsions include excessive hand-washing, arranging items in a particular way, and compulsive counting.

OCD is estimated to affect around 1 percent of adults in the United States. Of these adults, 50 percent have severe OCD, which can significantly interfere with daily life.

While the precise causes of OCD are unclear, previous studies have suggested that the disorder may be caused by specific gene mutations.

In the new study, researchers from Northwestern University in Chicago, IL, have pinpointed gene mutations in the corticostriatal region of the brain that led to OCD-like behaviors in mice.

Lead author Anis Contractor, associate professor of physiology at Feinberg School of Medicine, and colleagues recently reported their findings in the journal Cell Reports.

Eliminating KAR genes led to OCD-like behavior in mice

In humans and mice, the corticostriatal brain region is responsible for regulating repetitive behavior. “People with OCD are known to have abnormalities in function of corticostriatal circuits,” notes Contractor.

By analyzing this brain region in mice, Contractor and colleagues identified a number of synaptic receptors – called kainate receptors (KARs) – that play a key role in the development of the corticostriatal region.

The researchers then set out to investigate whether disrupting KAR genes in mice – thereby eliminating KARs – might induce repetitive behavior in the rodents. They found this was the case.

Mice whose KAR genes were erased displayed a number of OCD-like behaviors, such as over-grooming and repeatedly digging in their bedding.

The team says these findings provide further evidence that KAR genes play a role in OCD in humans, and a possible biological mechanism.

“A number of studies have found mutations in the kainate receptor genes that are associated with OCD or other neuropsychiatric and neurodevelopmental disorders in humans.

I believe our study, which found that a mouse with targeted mutations in these genes exhibited OCD-like behaviors, helps support the current genetic studies on neuropsychiatric and neurodevelopmental disorders in humans.”

Anis Contractor

The team suggests that in the future, KAR genes could be a target for the development of new drugs to treat OCD.